Supporting plates for rotating tools, such as tool attachments for hand drilling machines in a one-piece form from an elastomeric material have long been known. A front adhering surface, which is, for example, smooth so that a grinding or polishing disk can be glued to it, is provided with an adhesive back or completely or partially with a hook (Velcro) surface for simply attaching grinding or polishing disks with a suitable loop covering. When working with such a supporting plate, the grinding or polishing disk normally is not pressed with its complete surface against the workpiece. Instead, it is applied at an angle, the contacting area varying with the contacting pressure and the resilience of the material of the supporting plate. The grinding and polishing disks are used up rapidly and can therefore be exchanged easily. However, the supporting plates also experience wear and damage during inattentive work when the disks are exchanged too late, in the case of difficult surface configurations as well as when the resilience of the supporting plate is not adapted well.
In addition, there are stiff rotating tools for the fine machining of surfaces in the form of laminated grinding disks, for which strips of layers of working media, superimposed in laminated fashion, are applied on an exchangeable plate with formation of a raised, truncated cone shape, which usually is in contact with only a portion of the periphery with the surface that is to be machined. Such an exchangeable plate with a bayonet fitting or similar connection to an accommodating carrier is to be exchanged with the bearing, possibly damaged exchangeable plate body when the working media are used up.
However, such a laminated grinding disk is expensive. Moreover, the stiff nature of the laminated grinding disk requires relatively sensitive and careful work, so that punctiform unevennesses do not arise during the machining due to tilting.
It is an object of the invention to provide a supporting plate, the handling of which is not critical and which can be adapted with little cost to different work requirements and, when damaged in the region of the adhering surface, can be renewed inexpensively.
This objective is accomplished with a supporting plate of claim 1. Such a supporting plate permits conventional, advantageously priced grinding, polishing or similar disks to be used on an adhering surface, which lies on a plastically deformable plate and with that lies flat spread against the workpiece, which is to be processed, without the danger of the dangerous tilting. As exchangeable plate, this plate can be exchanged not only when there is wear or damage, but also when a softer or firmer contacting pressure is required. Likewise, such an exchangeable plate can be exchanged when, instead of a hook facing, a smooth, adhering surface for other working media disks is required.
A quick-change connection in the form of a bayonet connection, especially if the direction of rotation of the tool is fixed, makes possible a simple loosening in the opposite direction. It is self evident that the quick-change connection for this purpose can also be brought about readily in a different known manner, perhaps in the form of xe2x80x9cclipxe2x80x9d or locking connections.
It is particularly advantageous if the accommodating carrier, which lies behind on the drive side and is normally not exchanged, engages the interior of the exchangeable plate with a coupling continuation, so that the latter embraces towards the outside the plate material that is to be specified for the supporting forces but, on the inside, is reduced from the point of view of material and therefore also of material costs. Since this region does not have to yield, as does the edge, the interior region of the exchangeable plate can be supported rigidly on the accommodating carrier. In this region, the exchangeable plate, as a whole, can be interrupted to an annular shape or constructed only to a closed adhering surface at the front side as a thin covering surface.
Advantageously, the accommodating carrier can still have a flange around the inner quick-change connection, with which it supports the exchangeable plate over an annular region, so that the exchangeable plate can be constructed correspondingly thinner, material thus being saved.
In many cases, however, the exchangeable plate can also advantageously be constructed itself as a tool if the material-saving and flexible configuration of the exchangeable plate offers a brush-like refinement.
Two examples of the invention are shown in the drawings and described in greater detail in the following.